The present invention relates to the field of thermal regulation of a battery for a motor vehicle, in particular a rechargeable electric or hybrid vehicle (PHEV for plug-in hybrid electric vehicle), of which the batteries can be charged by hooking up to an external energy source at different types of charging points, usually connected to a conventional electrical network.
For this type of vehicle, the performance of a battery is very sensitive to the usage temperature thereof. The usage temperature of a battery is dependent on the external temperature, but also on other parameters, such as the driving of the driver, for example.
At low temperature, a battery is weak. In other words, during a charge phase, the charge time of said battery is longer and it charges less energy; and during a discharge phase, the autonomy of the battery is lower and the performance of said battery is reduced (in this case, a battery has in particular low power absorption capacities in the case of regenerative braking).
At high temperature, the battery demonstrates an improved performance compared with that at low temperature (improved charge time, more stored energy, improved recovery of energy), but at the detriment to its service life, which is reduced.
It is therefore important to manage the transfers of heat, in other words the thermal properties of a battery, in order to be able to use said battery in its optimal zone of operation.
In order to manage the thermal properties of a battery, the current prior art solutions consist of using temperature thresholds that are constant over time for the triggering and stopping of the cooling/heating. For example, the cooling can be triggered on the basis of a temperature of the battery greater than 28° C., and this cooling can be stopped as soon as the temperature of the battery reaches 15° C.
Document U.S. Pat. No. 6,624,615 is also known and discloses a method for managing the temperature of a battery of an electric vehicle, in which the temperature thresholds that make it possible to determine whether it is necessary to cool or to heat the battery vary with the state of charge thereof. A disadvantage of this solution is that the thresholds are constant over time, i.e. are independent of the driving manner. Consequently, they may lead to an overconsumption when the driver adopts a gentle driving manner and may lead to an overheating when the driver adopts a harsh driving manner.